Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 36: Surfaces and Films: Forces, Structure and Manipulation

O 36.4: Vortrag

Dienstag, 26. Februar 2008, 15:00–15:15, MA 041

Lateral Resolution in Piezoresponse Force Microscopy — Tobias Jungk, Akos Hoffmann, and •Elisabeth Soergel — Institute of Physics, University of Bonn, Wegelerstrasse 8, 53115 Bonn, Germany

Among the methods for visualization of ferroelectric domains piezoresponse force microscopy (PFM) has become a very common technique mainly due to its high lateral resolution without any need for specific sample preparation. Although domain structures are easily imaged with this method, the lateral resolution and thus the observed domain wall width is still under discussion. The reported values for the width of 180° domain walls scatter noticeably. These inconsistencies can be explained by the PFM background inherent to the experimental setup that can broaden the observed domain wall widths. In this contribution, we present a quantitative study of the resolution in PFM depending on the tip radius, the type of sample and the thickness of the sample. For bulk single crystals the measured linear dependency of the width of the domain wall on the tip radius using PFM is validated by a simple theoretical model. Independent on the crystal type (BaTiO3, KNbO3, KTP, LiNbO3, LiTaO3, PGO and SBN) the same lateral resolution was measured. Using a Ti-Pt-coated tip with a nominal radius of 15 nm the so far highest lateral resolution in bulk ferroelectric crystals of only 17 nm was obtained.